Combination condenser and oil separator



Mar 11 15 1927.

c F. c. BELL COMBINATION. CONDENSER AND OIL SEPARATOR Filed Feb. 5, 1924 w P w a Z E 5, D WM um m. J ww 11m 'M K A, M aw NW. y m

' ticularly adapted to use in refrigerating.

Patented Mar. 15, 1927.,

UNITED STATES FRED C. BELL, OF ALAMED'A, CALIFORNIA.

COMBINATION CONDENSER- AND OIL SEPARA'IOR.

Application filed February 5, 1924. Serial No. 690,791.

This invention relates to a combination condenser and 011 separator, and especially to a condenser and separator which is parplants where the refrigerant and the oil are permitted to mix and are continuously circulated through the system.

While there are a number of various types of refrigerating machines in more or less common use, they all can be definitely grouped into two distinct classifications, according to the methods involved; that is, first, where refrigeration is produced by the evaporation of some volatile liquid, and second, where refrigeration is effected by the compression, cooling and expansion of air or other gas without liquefaction.

The first classification can be sub-divided into three groups, according to whether the principles .of compression, absorption, or vacuum, are employed. Y

The compression system is chiefly used today and is the one with which the present application is concerned. Essentially a compression system includes a compressor, oil separator, .condenser, expansion valve, and an evaporator or expansion coil. In the compression process the refrigerant or c'oolingagent is recovered after each expansion by means of mechanical compression. WVith certain'variations in construction and arrangement of equipment, the compression process is adaptable to such refrigerating agents as ammonia, carbonic anhydride, ethyl chloride, propane, sulphur dioxide, etc.

. The gaseous refrigerant in a compression system must be sufliciently compressed and cooled to convert it to liquid form. Under compression alone it will still remain asv a gas due to the fact that the application of pressure raises the temperature above the liquefaction point. Some form of condenser must therefore be used. Prior to condensation, however, the gas is usually passed through a suitable oil separator or trap in order to free it ofany excess'lubricant thatmay have gained entry into the compressor or otherwise. From the oilseparaton the hot refrigerant then passes to the cooling coils of the condenser where its temperature is sufficiently lowered by means of cold circulatin water, to convert it to liquid-form. It is t en capable of serving as a cooling medium. This is brought about by passing it through an expansion or regulating valve to the expansion side of the system. Here by virtue of a considerable drop in pressure it evaporates and returns to its normal mercialplants. A number of small plants for domestic or home use are gradually appearing upon the market and it is obvious that such plants must be fairly simple and automatic in operation.

The present invention relates to a' small installation of this character and while different refrigerants may be employed, the present application will refer to the use of sulphur dioxide. Sulphur dioxide, as a liquid, is colorless and soluble in water, in

which solution it is strongly acidic.

Sulphu rdioxide, like some other low pressure refrigerants, has a decided afiinity for certain of the hydrocarbon components. It is, however, entirely possible to specially treat mineral oils of higher viscosities, the

removal of the component parts afl ected by sulphur dioxide thus rendering the residual oil quite satisfactory as a lubricant. With these facts in mind, it might be stated that the object of the present invention is to generally improve and simplify the construction and operation of small refrigerating plants; toprovide a plant'in which sulphur dioxide or a like refrigerant may freely intermingle with the lubricating oil; i

to provide a combined condenser and oil separator where the refrigerant and oil are automatically separated; and further, to provide a combined cooling means for the refrigerant and the oil which causes condensation of the refrigerant and'cooling of the oil, thereby permitting the oil to serve both as a lubricant for the compressor and as a cooling medium therefor.

One form which my invention may as-v sume is exemplified in the following description and illustrated in the accompanying drawings, in which the drawing is a side elevation showing the combined condenser and oil separator in section, the drawing also illustrating the expansion valve, the condenser and the expansion or cooling coils.

Referring to the drawing in detail, A indicates, in general, the combined condenser and oil separator forming the subject matter of the present application; B the expansion or cooling coils, C the expansion valve, and D the compressor. Any suitable form of compressor may be employed, but it is here illustrated by a rotary type which is driven by means of an electric motor or the like indicated at E.

Theintake side of the compressor is connected with two pipes such as indicated at 2' and 3; the pipe 3 delivering a lubricating oil to the compressor, while the pipe 2 is connected with the discharge end of the expansion or cooling coils. The compressor is otherwise provided with a single discharge pipe as indicated at 4. This pipe receives the discharging lubricating oil and also the compressed gases, the opposite end of the pipe being connected with the top of the combined condenser and oil separator as indicated at 5.

This device consists of an exterior cylindrical shell 6 and an interior cylindrical shell7. The outer shell or cylinder is provided with top 8 and bottom 9, and is closed to permit suitable pressures to be built up therein when the plant is in operation. The interior shell 7 is provided with a head mem ber 10 which serves as a deflecting plate as will hereinafter be described. The lower end of the cylinder extends to the pointindicated at 11 and is open to permit the lubrieating oil and the condensed refrigerant to freely enter, the inner cylinder being supported in the position shown by two or more legs as indicated at 12.

A suitable-number of perforations 13 are formed in the sides of the inner cylinder, near the bottom thereof, and a single perfoe ration or opening is formed near the top as indicated at 14., I

p The expansion valve C is connected on one side with the lower end of the exterior cylinder or container 6 by means of a pipe 15 which extends to the center of the cylinder, the other side of the expansion valve being connected by means of a pipe 16 with the expansion or cooliiigcoils B. 'The oil or lubrieating pipe 3 is connected with a feed or upper end of the pipe as indicated at 19. T

- e upper end of the pipe is completely, closed by the upper plate 19 but it is per- A pair of halide or deflecting plates is placed on the forated between the deflecting plates as indicated at 20 to permit oil to freely enter when the plant is in operation.

In actual practice when the plant is in operation, a refrigerant such as sulphur dioxide is maintained in a liquid state in the main container 6, the approximate level maintained being that indicated at 21. Oil is also maintained in the container and as it is lighter than the refrigerant it collects on top thereof, the approximate oil level maintained being that indicated at 22. \Vhen the compressor is in operation oil regulated by valve 17 is constantly entering the compressor through pipe 3, while expanded gases from the cooling coils are entering through the pipe 2. The gases are compressed during their passage through the compressor and they are discharged into the pipe 4 in a com pressed condition and as such are fairly hot. The oil is discharged into the same pipe and the gas and oil are therefore discharged therethrough and enter the main container 6 through the connection 5. A cooling coil 25 is mounted exterior of the inner cylinder 7 and water or the like is maintained in constant circulation therethrough. The hot gases and oil entering through the pipe 5 are deflected outwardly and are spread in all directions by the upper head 10. They thus come in contact with the cooling coil and are rapidly condensed, the oil and condensed liquidsettling down and collecting in the lower portion of the main container. The two liquids continuously tend to stratify the moment they settle as a liquid, and the oil and refrigerant contained in the intermediate annular chamber indicated at 26 are therefore more or less mixed. It is desiredto separate the two liquids as much as possible as a fairly pure oil should be delivered to the compressor and a fairly pure refrigerant to the expansion valve. The oil will not settle to the bottom but will pass through the openings 13 into the inverted cylinder 7 and thus work towards the center between the baflle plates. The condensed or liquefied refrigerant settles to thebottom of the outer cylinder 6. It is thus in a more or less pure state and will therefore enter the expansion valve as a substantially pure liquefied sulphur dioxide. This liquid expands the moment it is released by the expansion valve. Here by virtue of a considerable drop in pressure it evaporates and returns to its nor mal gaseous state. In so doing it absorbs heat from the surroundings, whatever these. may be. It is then returned to the compressor through the pipe 2 to commence the cycle of operation anew.

By combining the condenser and the 011 separator as one unit the whole installation is materially simplified. The oil vapors, 1f any, are condensed in unison with the refrigcrating gas, and as they are perlmtted to freely separate before repeating the cycle of operation fairly pure products of both may be obtained. The oil pipe or standard 18 extends upwardlyinto the inner drum or cylinder 7. The upper perforation 14 in the inner drum is provided for the purpose of equalizing pressure between the interior and the exterior thereof, thus maintaining equal levels between the liquids inside and outside. Due to the provision of the perforation 14 a small amount of'gas will enter but this will naturally condense on the inner cool surface of the drum and will run down the inner surface thereof and settle through the oil to the, bottom of the main container. The

lower baflie is provided for the purpose of preventing mixing of the refrigerant and oil by induced current as the orifice in the oil discharge pipe is comparatively close to the top or upper level of the liquefied refrigerant contained in the cylinders when the system has been fully charged.

The function of the inner drum is to bring the gas and oil into more intimate contact with the cooling coils and by so doing to obtain the best cooling, effect and condensation. The oil is cooled in unison with the refrigerant and it thus serves a two-fold purpose, first that of a lubricant for the compressor, andsecondly that of cooling the same. Numerous parts and complications are avoided and automatic operation is permitted.

'- While certain features of the present invention are more or less specifically illustrated, I wish it understood that various changes in form and proportion mav be resorted to within the scope of the appended claims. I similarly wish it understood that the materials and finish of the several parts employed may be such as the experience and judgment of'the manufacturer may dictate or various uses may demand.

Having thus described my invention, what I claim and desire to'secure by Letters Patent is- 1. A combination condenser and oil separator of the character described, comprising an outer closed cylindrical casing, an interliior cylindrical casing mounted therein and spaced therefrom to form an annular interior chamber, an inlet pipe in the top of the outer casing for the admission of gas and oil, a cooling coil in said annular chamber extending substantially from the top to the bottom thereof tocondense the gas and oil vapors, and to permit separation and stratification thereof, a discharge pipe for the condensed refrigerant, and a discharge pipe for the oil, said into the oil strata.

2. A combination condenser and oil-separator of the character described, comprising an outer closed cylindrical casing, an interior cylindrical casing mounted therein and H pipe extending upwardly spaced therefrom to form an annular interior chamber, an inlet pipein the top of the outer casing for the admission of gas and oil, a cooling coil in said annular chamber extending substantially from the top to the bottom thereof to condense the gas and oil vapors, and to permit separation and stratification thereof, a discharge pipe for the condensed refrigerant, a head member formed on the inner cylinder and on top thereof, said head member being spaced with relation to the top of the exterior container to form a spreading and deflecting plate, the lower end of said inner cylinder being open and being provided with perforations in the side to permit free entrance of the condensed refrigerant and the oil, and a discharge pipe for the oil, said pipe extend- I ing upwardly into the-inner cylinder.

3. 'A combination condenser and oil separator of the character described, comprising an outer closed cylindrical casing, an interior cylindrical casing mounted therein and spaced therefrom to form an annular interior chamber, an inlet pipe in the top of the I outer casing for the admission of gas and oil, a cooling coil in said annular chamber extending substantially from the top to the bottom thereof to condense the gas and oil vapors, and to permit separation and stratification thereof, a

discharge pipe for.

the condensed refrigerant, a head member v the inner cylinder, and a deflecting plate on the upper end of said pipe and forming a closure therefor, said pipe being perforated in its sides to permit entrance of oil.

4. A combination condenser and oil separator of the character described comprising an outer closedcylindrical casing, an interior cylindrical casing mounted therein and spaced therefrom to form an annular inte rior chamber. an inlet pipe in the ,top of the outer casing for the admission of gas and oil, a cooling coil in said annular chamber extending substantially from the top to the bottom thereof to condense the gas and oil vapors, and to permit separation and Stratification thereof, said innerv cylindrical casing being open at its lower end to permit oil to enter, a pipe connected with said inner casing to discharge the oil entering the same, and a pipe connected with the outer casin to discharge the refrigerant.

- FRED C. BELL.

]l1Si3 below the deflecting plate 

